Effect of Cycocel on Some Physiological Characteristics of Tow Olive Cultivars (Mary and Mission) under Drought Stress

Drought is the most important problems that restrict cultivation of horticultural crops in arid and semi-arid regions and olive (Olea europaea L.) as an important fruit trees grows in these regions. In order to investigate the effect of cycocel treatment on some physioligical characteristics of two olive cultivars (Mary and Mission), under the condition of drought stress, a greenhouse experiment was conducted taking into account three factors of: cycocel at three levels (0, 500 and 1000 mg L-1), drought stress of three levels (irrigated at 5, 10 and 15 days intervals) and tow olive cultivars (Mary and Mission) in a factorial experiment in frame of randomized complete block design with three replicates for the lasted four months. The results showed that increased periods of drought have increased the number of stomata per unit leaf area and decreased net photosynthesis, transpiration rate, stomatal conductance and dry weight of leaf, stem and root in both cultivars. Also, results showed that both cycocel concentrations increased the number of stomata per unit leaf area, increase net photosynthesis, transpiration rate, stomatal conductance and dry weight of leaf; but no significant difference in dry weight of stem and root was observed compared with the control. In above-mentioned parameters, Mission cultivar showed higher resistance to drought stress than the Mary cultivar. Collectively, results suggested that the use of cycocel can be improved in photosynthesis under drought stress conditions.